Update to Zig 0.16.0

This commit represents the majority of the work necessary to upgrade
Ghostty to use Zig 0.16.0.

Key parts:

* In addition to its previous responsibilities, the global state now
  houses state for global I/O implementations and the process
  environment. It is now also utilized in the main application along
  with the C library. Where necessary, global state is isolated from key
  parts of the implementation (e.g., in libghostty subsystems), and it's
  expected that this list will grow.

* We currently manage our own C translation layer where necessary. In
  these cases, cImport has been removed in favor of the new external
  translate-c package. Due to fixes that have needed be made to properly
  translate the dependencies that were swapped out, as mentioned, we
  have had to backport fixes from the current translate-c package (and
  the upstream Arocc dependency). We will host this ourselves until Zig
  0.17.0 is released with these fixes.

* Where necessary (only a small number of cases), some stdlib code from
  0.15.2 (and even from 0.17.0) has been taken, adopted, and vendored in
  lib/compat.

Co-authored-by: Leah Amelia Chen <hi@pluie.me>

example/zig-formatter/src/main.zig

@@ -1,24 +1,20 @@
 const std = @import("std");
 const ghostty_vt = @import("ghostty-vt");
 
-pub fn main() !void {
-    var gpa: std.heap.DebugAllocator(.{}) = .init;
-    defer _ = gpa.deinit();
-    const alloc = gpa.allocator();
-
+pub fn main(init: std.process.Init) !void {
     // Create a terminal
-    var t: ghostty_vt.Terminal = try .init(alloc, .{ .cols = 150, .rows = 80 });
-    defer t.deinit(alloc);
+    var t: ghostty_vt.Terminal = try .init(init.io, init.gpa, .{ .cols = 150, .rows = 80 });
+    defer t.deinit(init.gpa);
 
     // Create a read-only VT stream for parsing terminal sequences
     var stream = t.vtStream();
     defer stream.deinit();
 
     // Read from stdin
-    const stdin = std.fs.File.stdin();
+    const stdin = std.Io.File.stdin();
     var buf: [4096]u8 = undefined;
     while (true) {
-        const n = try stdin.readAll(&buf);
+        const n = try stdin.readStreaming(init.io, &.{&buf});
         if (n == 0) break;
 
         // Replace \n with \r\n
@@ -35,7 +31,7 @@ pub fn main() !void {
     });
 
     // Write to stdout
-    var stdout_writer = std.fs.File.stdout().writer(&buf);
+    var stdout_writer = std.Io.File.stdout().writer(init.io, &buf);
     const stdout = &stdout_writer.interface;
     try stdout.print("{f}", .{formatter});
     try stdout.flush();

example/zig-vt-stream/src/main.zig

@@ -1,13 +1,9 @@
 const std = @import("std");
 const ghostty_vt = @import("ghostty-vt");
 
-pub fn main() !void {
-    var gpa: std.heap.DebugAllocator(.{}) = .init;
-    defer _ = gpa.deinit();
-    const alloc = gpa.allocator();
-
-    var t: ghostty_vt.Terminal = try .init(alloc, .{ .cols = 80, .rows = 24 });
-    defer t.deinit(alloc);
+pub fn main(init: std.process.Init) !void {
+    var t: ghostty_vt.Terminal = try .init(init.io, init.gpa, .{ .cols = 80, .rows = 24 });
+    defer t.deinit(init.gpa);
 
     // Create a read-only VT stream for parsing terminal sequences
     var stream = t.vtStream();
@@ -34,7 +30,7 @@ pub fn main() !void {
     stream.nextSlice("Line A\r\nLine B\r\nLine C\r\n");
 
     // Get the final terminal state as a plain string
-    const str = try t.plainString(alloc);
-    defer alloc.free(str);
+    const str = try t.plainString(init.gpa);
+    defer init.gpa.free(str);
     std.debug.print("{s}\n", .{str});
 }

example/zig-vt/src/main.zig

@@ -1,26 +1,20 @@
 const std = @import("std");
 const ghostty_vt = @import("ghostty-vt");
 
-pub fn main() !void {
-    // Use a debug allocator so we get leak checking. You probably want
-    // to replace this for release builds.
-    var gpa: std.heap.DebugAllocator(.{}) = .init;
-    defer _ = gpa.deinit();
-    const alloc = gpa.allocator();
-
+pub fn main(init: std.process.Init) !void {
     // Initialize a terminal.
-    var t: ghostty_vt.Terminal = try .init(alloc, .{
+    var t: ghostty_vt.Terminal = try .init(init.io, init.gpa, .{
         .cols = 6,
         .rows = 40,
     });
-    defer t.deinit(alloc);
+    defer t.deinit(init.gpa);
 
     // Write some text. It'll wrap because this is too long for our
     // columns size above (6).
     try t.printString("Hello, World!");
 
     // Get the plain string view of the terminal screen.
-    const str = try t.plainString(alloc);
-    defer alloc.free(str);
+    const str = try t.plainString(init.gpa);
+    defer init.gpa.free(str);
     std.debug.print("{s}\n", .{str});
 }